Vehicles, such as automobiles, are assembled by aligning and fastening numerous components and subassemblies to one another. One region of the automobile requiring assembly of such components and subassemblies is a front end region. This portion of the vehicle is frequently assembled as an assembly or subassembly referred to as a “front clip.” The front clip is commonly defined as the assembly comprising the portion of the vehicle extending from the A-pillar (the roof support pillar associated with the front windscreen) to the most forwardly disposed component, typically a front bumper. The front clip includes a structural frame, as well as a variety of vehicle components that collectively form the vehicle body.
Several efforts to directly or indirectly mount and/or fix the vehicle body components to each other, as well as to the vehicle frame, have relied on welded support structures or frames and machined body mounting locations for the body components. Front end clips that use welded frames to attach front clip components are effective, but they generally require very large capital investments to support automated, high volume mass production. Frameless approaches for assembly of the front end clip are very desirable because they have greatly reduced capital requirements, but have sometimes been subject to undesirably large variations in alignment and fastening of components to one other. These large variations may influence the aesthetic appearance of the automobile to a user by providing non-uniform or undesirably large or small gaps and spacings between components and may be the cause of functional deficiencies, such as undesirable large opening/closing efforts, alignment and mutilation of components due to misalignment and interference, and non-uniform gaps and spacings, which each may affect consumer satisfaction.
Frameless front clip assembly requires the use of structural fenders as compared to frame-based front end clip construction where the fender sheet metal may be attached directly to the frame and the frame provides much of the needed structural strength. One area of concern in frameless front clip assemblies that use structural fenders, such as the front end sheet metal of the floating structure of a full size truck, has been the development of structural fenders and methods of making and using them so as to set the structural fender in an optimal position to ensure predetermined requirements. These requirements include aesthetic requirements, such as gap, spacing, class A finish and other aesthetic requirements, as well as structural function requirements, such as strength and modal frequency response, and overall vehicle requirements, such as, for example, selectively controllable frontal impact response. For example, it is frequently desirable to increase the strength and stiffness of the structural front fenders to improve vehicle ride and handling. However, while increased strength and stiffness improves ride and handling under normal operating conditions, these characteristics may over constrain the structural fender during a frontal impact, where it is desirable that the structural fender have a selectively controllable deformation characteristic to provide a predetermined energy absorption of the impact energy.
Accordingly, it is desirable to provide structural fenders that meet the structural requirements for strength and stiffness and that also provide a selectively controllable deformation characteristic.